Swingable doors are doors which are hinged to a frame structure or otherwise pivot about an axis. Such doors are used in thousands of different applications including homes, office buildings, automobiles, cabinets, display cases, refrigerators, and the like. Inventors have therefore expended great effort to develop and improve swingable doors and hinges for such doors.
It is sometimes desirable to provide a hinge assembly including means for automatically closing an associated swingable door after the door has been opened. For example, when swingable doors are used on refrigerators, it is desirable for the doors to include hinge assemblies which automatically urge them to a closed position. It is particularly desirable to use automatic closing swingable doors for refrigerator display cases in commercial environments as customers often open refrigerator display cases to obtain products stored therein and thereafter walk away from the open refrigerated display case without closing the door.
One type of hinge assembly which is used to automatically urge a swingable door into a closed position includes a torsion rod as part of its structure. Torsion rods permit hinge assemblies to be preloaded with a predetermined amount of torsion force to urge an associated swingable door into its closed position.
In order to accomplish this automatic closing force, a torsion rod may typically be an elongate rod which is fixed at one end and which may be twisted at the other end so that the inherent nature of the material and dimensions of the rod will exert a torsion force after it has been rotated.
Certain refrigerated display cases may use swingable doors which rotate about a hinge assembly in a clockwise direction in order to open the door. Such doors may swing open to the left. In other embodiments, the swingable doors may open in the opposite direction (i.e., to the right) and thus rotate counter clockwise about their hinge axis.
Ratchet assemblies are typically used as part of hinge assemblies to preload a torsion spring and permit rotation in a single direction (i.e., clockwise or counter clockwise) while prohibiting rotation in the other direction. Such ratchet assemblies are known in the art and typically include a pair of ratchets arranged in abutment with each other on a hinge assembly. The abutting ratchets may include meshed-face type teeth which are adapted to permit rotation of the ratchets in either the clockwise or counter clockwise direction with respect to each other, while inhibiting rotation in the other direction.
Certain prior art swingable doors which include preloaded hinge assemblies can be reversed so that they open in an opposite direction from the original swinging direction. Reversal of the swingable doors have heretofore been accomplished upon removal of the doors from their assembled position, flipping the doors over and mounting them on a different side of an associated case.
One type of reversible prior art swingable door includes a relatively large rectangular cut-out area in the sash of the door which is necessary to provide access for an Allen wrench, or other tool which must interact with the hinge assembly in order to accomplish preloading and adjustment. These prior art doors are undesirable because the large cut-out area weakens the door structure.
Another disadvantage of prior art preloaded hinge assemblies is that they are difficult to remove when repairs are necessary. In particular, the entire door frame must be disassembled in order to remove the prior art preloaded hinge assemblies. This process is time consuming and complicated. Further, prior art doors which require at least partial disassembly to remove and replace components of the hinge assembly are limited in their design. To this end, unified bonded glass and frame doors cannot be used with hinge assemblies which are only accessible after disassembly at the door frame.